The invention provides a method of changing the mounting condition of a printing master on a printing master cylinder including a first receiving element for the leading edge and a second receiving element for the trailing edge of the printing master, wherein the printing master cylinder is rotated at a first speed and the first receiving element is actuated in at least one first phase position and the second receiving element is actuated in at least one second phase position. In addition, the invention provides a printing unit, in particular in a printing press, which comprises at least one printing master cylinder and a control unit including a processing unit with a memory.
To reproduce various printing images in a printing press, printing image carriers or printing masters generally referred to as printing forms or printing plates, with varying contents are mounted to printing master cylinders in the printing units of the printing press. To mount and dismount a printing master, the printing master cylinder is rotated at a constant speed. Receiving elements, which may be integrated, if desired, to form a mounting device, are provided for the leading edge and the trailing edge of the printing master. The receiving elements are actuated to lock or release the leading edge and the trailing edge, respectively, of the printing master in anticipation of the required phase position (i.e. the rotary position, the angular position, or the orientation) of the printing master cylinder relative to a zero position of the press or a point of contact with a transfer cylinder, especially a blanket cylinder, or a printing master changing device.
The document JP 2000-272096A discloses a method of mounting and a method of dismounting a printing master. For the printing master to be inserted into or removed from the receiving elements, which are embodied as clamping bars, the printing press is stopped in a defined phase position.